1. Technical Field
Aspects of the present invention relate to wireless communications. More particularly, aspects of the present invention relate to maintaining connectivity while roaming between wireless networks.
2. Related Art
Different wireless technologies exist for mobile data users. Mobile data users may use cellular technologies, IEEE 802.11-based technologies, Bluetooth and other wireless technologies to connect to a network. While hand off between access points in a singular network is well known, hand off between access points running divergent wireless protocols is difficult. Here, users desire seamless mobility despite network changes. Further, so as to protect networks from unwanted intrusion, multiple firewalls may be used at locations across networks. One downside is that firewalls prevent users from freely accessing their networks. Accordingly, users need a solution that provides both mobility and secure access to their home networks.
Mobile IP systems include mobile IP client software on a user terminal and a mobile IP home agent (HA) in a network's infrastructure, the home agent controls the topological correct address of the mobile node (here referred to as a home address) and maintains a binding list (here referred to as a care-of address) with the current location of a mobile node (MN). The mobile node updates the home agent with its current care-of-address. This may happen directly or, optionally, by means of an intermediate foreign agent (FA). The home agent sets up a forward tunnel to redirect traffic from the topological he correct home address to the current care-of-address. The tunnel or arises from packet  encapsulation performed by the home agent. Fort reference, any non-mobile host may be referred to as a correspondent node (CN).
Seamless IP mobility, when combined with a secure connection, allows users to access their home networks from remote locations. Remote VPN technologies permit this type of connection between a mobile node and a VPN Gateway (VPNgw) local to a correspondent node. A VPN solution includes both totaling and encryption to maintain two vacation from a secure domain to a terminal that is remotely connected from an insecure location in a different domain. The VPN solution is usually a preferred way to reach components inside the secure domain.
One approach to creating VPN tunnels across firewalls is by using an architecture as shown in FIG. 1. FIG. 1 includes the TCP IP layer 101, and internal mobile IP driver (i-MIP) 102, a VPN 103, an external mobile IP driver (x-MIP) 104, and two network interface drivers (network driver A 105 and network driver B 106). Here, TCP IP layer 101 may connect with the network drivers A 105 and B 106 by three pathways. The first pathway is through i-MIP driver 102, VPN 103, and x-MIP driver 104. This is generally the most secure remote connection available. The second pathway is through i-MIP driver 102 and x-MIP driver 104. This is also a remote connection. The third pathway is directly from TCP/IP layer 101 to x-MIP driver 104. This third connection is used when, for instance, a mobile node is inside the firewalls surrounding a correspondent node.
The approach of FIG. 1 does not readily provide seamless transitions between network driver A 105 and network driver B 106. This is because x-MIP driver 104 handles the local connection pathway as well as the other pathways. When the using the local connection path, x-MIP driver 104 is readily processing the information on that pathway. If a user then requests a VPN connection to be established, the x-MIP driver 104 would then need to drop the current connection, establish the VPN pathway, and then re-establish the connection with the network driver A 105.
Accordingly, an improved system for seamless roaming is needed. 